Optical coherence tomography (OCT) and OCT-angiography in syndromic versus non-syndromic USH2A-associated retinopathy

PURPOSE

To compare non-syndromic and syndromic forms of USH2A-related retinitis pigmentosa (RP) by means of structural optical coherence tomography (OCT) and OCT-angiography (OCTA).

METHODS

Observational, cross-sectional, multicenter study. All patients underwent best corrected visual acuity (BCVA) measurement, OCT (Spectralis HRA + OCT, Heidelberg Engineering) and OCTA (OCT DRI Topcon Triton, Topcon Corporation). We compared subfoveal choroidal thickness (SCT), choroidal vascularity index (CVI), presence of cystroid macular edema (CME), macular vessel density (VD) at the superficial and deep capillary plexa, as well as VD of the radial peripapillary capillary (RPC) network, between syndromic and non-syndromic patients with USH2A-associated retinopathy.

RESULTS

Thirty-four eyes from 18 patients (7 females) were included. Thirteen patients (72.2%) were affected by Usher syndrome type 2, whereas the remaining 5 subjects (27.8%) had non-syndromic retinitis pigmentosa (nsRP). Syndromic patients were younger than nsRP (p = 0.01) and had a worse visual acuity than those with the exclusively retinal phenotype. Patients with Usher syndrome type 2 had a higher prevalence of CME and a thicker choroid compared to nsRP, although these results were not statistically significant (p = 0.775 and p = 0.122, respectively). Similarly, none of the other quantitative OCT and OCTA parameters was statistically different between the two groups.

CONCLUSIONS

Despite their younger age, patients with Usher syndrome type 2 displayed similar choroidal and microvascular changes compared to those with nsRP.

Extensive Macular Atrophy with Pseudodrusen-like appearance (EMAP): progression kinetics and late-stage findings

PURPOSE

To describe the clinical outcome and late-stage findings of Extensive Macular Atrophy with Pseudodrusen-like appearance (EMAP).

STUDY DESIGN

Retrospective cohort study.

PARTICIPANTS

Seventy-eight patients (156 eyes) affected by EMAP.

METHODS

We collected data on best-corrected visual acuity (BCVA), kinetic perimetry, optical coherence tomography (OCT), short-wavelength autofluorescence (SW-AF) and near-infrared autofluorescence (NIR-AF). Genetic testing for the TIMP3 and C1QTNF5 genes was performed via Sanger sequencing for 58 subjects, with no pathogenic variants identified.

MAIN OUTCOME MEASURES

BCVA, visual field, and imaging findings at the last examination. Incidence rates and time-to-event curves for blindness with the United States Social Security Administration (US-SSA) and World Health Organization (WHO) criteria, foveal involvement, and atrophy enlargement beyond the 30° and 55° field of view.

RESULTS

At the most recent visit, the mean age was 70.9 ± 5.2 years. 58.1% of the patients were blind with the US criteria, and 25.8% according to the WHO. All eyes had large central scotomas, in 22.7% of the cases associated with visual field constriction. We detected focal openings or large dehiscences of the Bruch's membrane in 25.4% of the eyes. NIR-AF shows increased visibility of the choroidal vessels beyond the atrophy in 87.2% of the eyes. The incidence rates for blindness were 3.95/100-subjects-year with the US criteria and 1.54/100-subjects-year according to the WHO. The incidence rates were 22.8/100-eye-year for foveal involvement, 12.0/100-eye-year for atrophy enlargement beyond the 30° and 6.6/100-eye-year for atrophy enlargement beyond 55°. The estimates were not influenced by the age of onset.

CONCLUSION

We identified characteristic imaging findings, including Bruch's membrane ruptures, in elder EMAP patients and calculated incidence rates for different functional and anatomical outcomes.

Multimodal Imaging of Vitreo-Retinal Lymphoma: A Comprehensive Review

PURPOSE

Vitreoretinal lymphoma (VRL) is a rare lymphoma affecting the vitreous and the retina. Clinical diagnosis is challenging and often delayed and may lead to aggravated prognosis. This study aims to review multimodal imaging findings in VRL.

METHODS

We performed a comprehensive narrative review of the multimodal imaging findings that might be useful in the detection of VRL lesions.

RESULTS

The most frequent ocular manifestations of VRL are vitritis, and retinal and sub-retinal Pigmented Epithelium (RPE) infiltrations. Color Fundus Photography (CFP) detects vitreous haze, optic nerve, retinal and sub-RPE infiltration. Ultra-wide field imaging allows visualization of different patterns of vitreous haze and monitoring of VRL evolution through the detection of chorio-retinal atrophy (CRA). Fundus Autofluorescence shows granular hypo- and hyper-autofluorescent pattern. Optical Coherence Tomography (OCT) reveals vitreous cells, vertical hyper-reflective lesions and sub-RPE infiltrates. Fluorescein Angiography (FA) shows hypo or hyperfluorescent round lesions at the late stages of the examination, while Indocyanine Green Angiography (ICGA) detects round areas of focal hypo-fluorescence in the early phases that gradually enlarge in the late phases. B-scan ultrasonography detects vitreous opacities and homogeneous hyperreflective corpuscular material in the vitreous, and is a strongly recommended tool in suspecting VRL and is particularly useful when vitreous haze is impeding retinal examination.

CONCLUSION

Diagnostic vitrectomy with cytopathological analysis remains the gold standard for VRL diagnosis, however multimodal imaging allows the identification of suggestive retinal and vitreal lesions for early suspicion, diagnosis, and treatment and monitoring disease progression and response to treatment.

The Retinal Phenotype Associated with the p.Pro101Thr BEST1 Variant

PURPOSE

To describe the retinal phenotype associated with the p.Pro101Thr BEST1 variant.

DESIGN

Retrospective, observational case series.

PARTICIPANTS

Patients diagnosed with bestrophinopathies in which molecular genetic testing identified the p.Pro101Thr BEST1 as well as healthy carriers among their first-degree relatives.

METHODS

Medical records were reviewed to obtain data on family history and ophthalmic examinations, including retinal imaging. The imaging protocol included OCT and fundus autofluorescence using Spectralis HRA + OCT (Heidelberg Engineering). Genetic analysis was performed by next-generation sequencing.

MAIN OUTCOME MEASURES

Results of ophthalmic examinations and multimodal imaging features of retinal phenotypes.

RESULTS

The c.301C>A, p.Pro101Thr BEST1 missense variant was identified as the causative variant in 8 individuals (all men) from 5 families, accounting for 13% of cases (8/61) and 10% of pathogenic alleles (9/93) in our cohort of patients affected by bestrophinopathies. Seven individuals (14 eyes) had the variant in heterozygous status: all eyes had a hyperopic refractive error (median spherical equivalent of + 3.75 diopters [D]) and 4 individuals had a macular dystrophy with mildly reduced visual acuity (median of 20/25 Snellen), whereas the other 3 were asymptomatic carriers. On multimodal retinal imaging, 5 (36%) out of 14 eyes had subclinical bestrophinopathy, 4 (29%) had typical findings of adult-onset foveomacular vitelliform dystrophy (AOFVD), and the remaining 5 (36%) displayed a pattern dystrophy-like phenotype. Follow-up data were available for 6 subjects, demonstrating clinical stability up to 11 years, in both subclinical and clinical forms. An additional patient with autosomal recessive bestrophinopathy was found to harbor the p.Pro101Thr variant in homozygosity.

CONCLUSIONS

The p.Pro101Thr BEST1 variant is likely a frequent cause of bestrophinopathy in the Italian population and can result in autosomal dominant macular dystrophies with incomplete penetrance and mild clinical manifestations as well as autosomal recessive bestrophinopathy. The spectrum of autosomal dominant maculopathy includes the typical AOFVD and a pattern dystrophy-like phenotype.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

New insights in the multimodal imaging of retinitis pigmentosa

Retinitis pigmentosa (RP) is a group of inherited rod-cone dystrophies, noted for a high genotypical and phenotypical heterogeneity.Traditionally, VA, visual field, and electroretinography have been used to assess RP progression. However, visual acuity and visual field tests are essentially subjective and, especially in the late stages of the disease, are unable to confidently reveal minor progression. Therefore, there is a need for novel examination modalities that rely on quantitative, structural measurements. In this regard, several non-invasive imaging techniques have been studied, including spectral-domain optical coherence tomography, optical coherence tomography angiography, and fundus autofluorescence. By correlating surrogate biomarkers with functional measurements of the disease, these techniques may be able to develop reliable outcome meters that can be used to gain a deeper understanding of the underlying causes of the disease and to assess the effectiveness of therapy even before an actual loss of vision occurs.In this review, we will summarize the recent imaging findings and biomarkers that have been identified in RP patients. Our goal is to provide information that can promptly aid in selecting patients for clinical trials and new gene therapies, monitoring the disease progression, and evaluating treatment outcomes.

Inner retinal thickness in Stargardt disease

PURPOSE

To analyze the alterations at the level of the inner retina in patients affected by Stargardt disease (STGD1).

METHODS

Cross-sectional investigation involving STGD1 patients with genetically confirmed diagnosis, who underwent optical coherence tomography (OCT), optical coherence tomography angiography (OCTA), and microperimetry.

RESULTS

Overall, 31 patients (62 eyes) with genetically confirmed STGD1 were included in the study. Mean inner retinal thickness, vessel density of plexa, and retinal sensitivity resulted significantly reduced in STGD patients, compared with healthy controls (p < 0.05), both in the outer and in the inner ETDRS rings. Overall, 43% of eyes revealed an inner retinal thinning, whereas 21% and 35% showed a thicker or within normal range inner retina.

CONCLUSIONS

Inner retina is irregularly altered in STGD1, showing variable quantitative alterations as detected on OCT. Inner retinal status might represent a useful biomarker to better characterize STGD1 and to ascertain the effects of new treatment approaches.

Non-vasogenic cystoid maculopathy in autosomal recessive bestrophinopathy: novel insights from NIR-FAF and OCTA imaging

BACKGROUND

Autosomal Recessive Bestrophinopathy (ARB) is an inherited retinal disease caused by biallelic mutations in the BEST1 gene. Herein, we report the multimodal imaging findings of ARB presenting with cystoid maculopathy and investigate the short-term response to combined systemic and topical carbonic anhydrase inhibitors (CAIs).

MATERIAL AND METHODS

An observational, prospective, case series on two siblings affected by ARB is presented. Patients underwent genetic testing and optical coherence tomography (OCT), blue-light fundus autofluorescence (BL-FAF), near-infrared fundus autofluorescence (NIR-FAF), fluorescein angiography (FA), MultiColor imaging, and OCT angiography (OCTA).

RESULTS

Two male siblings, aged 22 and 16, affected by ARB resulting from c.598C>T, p.(Arg200*) and c.728C>A, p.(Ala243Glu) BEST1 compound heterozygous variants, presented with bilateral multifocal yellowish pigment deposits scattered through the posterior pole that corresponded to hyperautofluorescent deposits on BL-FAF. Vice versa, NIR-FAF mainly disclosed wide hypoautofluorescent areas in the macula. A cystoid maculopathy and shallow subretinal fluid were evident on structural OCT, albeit without evidence of dye leakage or pooling on FA. OCTA demonstrated disruption of the choriocapillaris throughout the posterior pole and sparing of intraretinal capillary plexuses. Six months of combined therapy with oral acetazolamide and topical brinzolamide resulted in limited clinical benefit.

CONCLUSIONS

We reported two siblings affected by ARB, presenting as non-vasogenic cystoid maculopathy. Prominent alteration of NIR-FAF signal and concomitant choriocapillaris rarefaction on OCTA were noted in the macula. The limited short-term response to combined systemic and topical CAIs might be explained by the impairment of the RPE-CC complex.

Variants in UBAP1L lead to autosomal recessive rod-cone and cone-rod dystrophy

PURPOSE

Progressive inherited retinal degenerations (IRDs) affecting rods and cones are clinically and genetically heterogeneous and can lead to blindness with limited therapeutic options. The major gene defects have been identified in subjects of European and Asian descent with only few reports of North African descent.

METHODS

Genome, targeted next-generation, and Sanger sequencing was applied to cohort of ∼4000 IRDs cases. Expression analyses were performed including Chip-seq database analyses, on human-derived retinal organoids (ROs), retinal pigment epithelium cells, and zebrafish. Variants' pathogenicity was accessed using 3D-modeling and/or ROs.

RESULTS

Here, we identified a novel gene defect with three distinct pathogenic variants in UBAP1L in 4 independent autosomal recessive IRD cases from Tunisia. UBAP1L is expressed in the retinal pigment epithelium and retina, specifically in rods and cones, in line with the phenotype. It encodes Ubiquitin-associated protein 1-like, containing a solenoid of overlapping ubiquitin-associated domain, predicted to interact with ubiquitin. In silico and in vitro studies, including 3D-modeling and ROs revealed that the solenoid of overlapping ubiquitin-associated domain is truncated and thus ubiquitin binding most likely abolished secondary to all variants identified herein.

CONCLUSION

Biallelic UBAP1L variants are a novel cause of IRDs, most likely enriched in the North African population.

Multimodal imaging in Best Vitelliform Macular Dystrophy: Literature review and novel insights

Best Vitelliform Macular Dystrophy (BVMD) is a dominantly inherited retinal disease caused by dominant variants in the BEST1 gene. The original classification of BVMD is based on biomicroscopy and color fundus photography (CFP); however, advancements in retinal imaging provided unique structural, vascular, and functional data and novel insights on disease pathogenesis. Quantitative fundus autofluorescence studies informed us that lipofuscin accumulation, the hallmark of BVMD, is unlikely to be a primary effect of the genetic defect. It could be due to a lack of apposition between photoreceptors and retinal pigment epithelium in the macula with subsequent accumulation of shed outer segments over time. Optical Coherence Tomography (OCT) and adaptive optics imaging revealed that vitelliform lesions are characterized by progressive changes in the cone mosaic corresponding to a thinning of the outer nuclear layer and then disruption of the ellipsoid zone, which are associated with a decreased sensitivity and visual acuity. Therefore, an OCT staging system based on lesion composition, thus reflecting disease evolution, has been recently developed. Lastly, the emerging role of OCT Angiography proved a greater prevalence of macular neovascularization, the majority of which are non-exudative and develop in late disease stages. In conclusion, effective diagnosis, staging, and clinical management of BVMD will likely require a deep understanding of the multimodal imaging features of this disease.

Non-perfusion severity correlates with central macular thickness and microvascular impairment in branch retinal vein occlusions

PURPOSE

To study peripheral capillary non-perfusion (PCN-P) in branch retinal vein occlusion (BRVO) by means of ultra wide-field fluorescein angiography (UWFFA), and to correlate its extent and severity with optical coherence tomography (OCT) and OCT-angiography (OCTA) parameters and best corrected visual acuity (BCVA).

METHODS

Prospective case series with 2 years of planned follow-up. We recruited patients from June 2019 to December 2019. Ophthalmologic examination included BCVA, UWFFA, OCT and OCTA. Partial (p) and complete (c) ischemic index (ISI) were evaluated on UWFFA images. Vessel density (VD) in both the macular region and the optic nerve head (ONH) was calculated.

RESULTS

Twelve BRVO subjects and 12 healthy controls were recruited. Mean age was 63.8  ±  8.74 years. Mean BCVA improved from 0.43  ±  0.25 logMAR to 0.15  ±  0.18 after two years (p < 0.01), while mean central macular thickness (CMT) decreased from 463.83  ±  200.85 µm to 353.17  ±  108.85 µm (p > 0.05). Mean cISI, pISI and total ISI were 25.2  ±  13.0%, 6.3  ±  5.0% and 31.5  ±  12.0%, respectively. Except for VDs of the superficial capillary plexus and choriocapillaris in the macular region, all VDs were lower in the BRVO group (p < 0.01). cISI and tISI negatively correlated with mDCP (p < 0.01), whereas only pISI correlated with CMT at baseline (p < 0.05). Additionally, cISI also negatively correlated with VD at the ONH (p < 0.05).

CONCLUSION

The amount of complete and partial ischemia may have different implications in BRVO, with the former being more associated with microvascular impairment and the latter with macular edema.

Association of Circulating Antiretinal Antibodies With Clinical Outcomes in Retinitis Pigmentosa

Purpose

To determine if circulating antiretinal antibodies (ARAs) differ between patients affected by retinitis pigmentosa (RP) and control participants and to assess whether ARAs are associated with clinical outcomes in patients with RP.

Methods

Cross-sectional study involving a group of patients clinically diagnosed with RP and a control group of healthy participants. Serum autoantibodies against enolase, heat shock protein 70 (HSP70), and carbonic anhydrase II (CAII) were tested in all participants using Jess capillary Western blot. We compared ARA prevalence between the RP and control groups and investigated the association of serum ARA positivity with macular edema and vitreomacular disorders in patients affected by RP.

Results

Thirty-six patients affected by RP and a control group of 39 healthy individuals were included. Overall, at least one ARA positivity was detected in 89% and 80% of participants in the RP and control groups, respectively. We observed a similar prevalence of anti-CAII and anti-enolase ARA between patients and controls (P = 0.87 and P = 0.35, respectively). Sera from patients with RP tested positive for anti-HSP70 ARAs more frequently than those from controls (53% vs. 36%), albeit without reaching statistical significance (P = 0.29). Among the 72 eyes with RP, 25% presented with macular edema (most often bilateral) and 33% with epiretinal membrane and/or lamellar macular hole. None of the three ARAs was associated with an increased risk of any macular complications in eyes affected by RP (all P > 0.05).

Conclusions

The prevalence of circulating ARAs against enolase, HSP70, and CAII is similar between patients affected by RP and healthy individuals. Our results provide evidence against the association of ARAs with macular edema and vitreomacular interface disorders in RP.

The Localization of Intraretinal Cysts Has a Clinical Role on the 2-Year Outcome of Neovascular Age-Related Macular Degeneration

OBJECTIVE

To assess the relationship between ≥ 1 localizations of intraretinal fluid (IRF) within retinal layers and the 2-year outcome in a cohort of neovascular age-related macular degeneration (AMD) eyes.

DESIGN

Retrospective case series.

PARTICIPANTS

Two hundred forty-three eyes of 243 AMD patients affected by type 1 and type 2 macular neovascularization (MNV).

METHODS

We analyzed data considering MNV onset, 1-year, and 2-year timepoints. Optical coherence tomography images were used to classify MNV types, distinguish different types of fluids and assess IRF localization within retinal layers. A subcohort of eyes were also analyzed by OCT angiography.

MAIN OUTCOME MEASURES

The association between IRF cyst localization and both visual outcome and onset of outer retinal atrophy at 2-year follow-up.

RESULTS

Macular neovascularizations were distributed as type 1 (69%) and type 2 (31%). The mean number of intravitreal injections was 7 ± 2 at 1-year follow-up and 5 ± 2 at 2-year follow-up. Baseline best-corrected visual acuity was 0.4 ± 0.3 logarithm of the minimum angle of resolution, improving to 0.3 ± 0.4 at 2-year follow-up (P < 0.01). Outer retinal atrophy occurred in 24% of cases at 1 year and 39% of cases at 2-year follow-up. Intraretinal fluid localizations at the level of IPL-INL and OPL-ONL at baseline were associated with the worst functional and anatomical outcome. Moreover, the presence of IRF at baseline was associated with greater impairment of the intraretinal vascular network.

CONCLUSIONS

The localization of IRF at the level of IPL-INL and OPL-ONL retinal layers represents a negative prognostic biomarker for the morphologic and functional outcomes of neovascular AMD.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Fixation Location and Stability in Best Vitelliform Macular Dystrophy

Purpose

To analyze fixation location and stability in best vitelliform macular dystrophy (BVMD) and test their association with best-corrected visual acuity (BCVA).

Design

Observational, cross-sectional study.

Participants

Thirty patients (55 eyes) affected by genetically confirmed BVMD were followed up at the Retinal Heredodystrophies Unit of IRCCS San Raffaele Scientific Institute, Milan.

Methods

Patients underwent testing with macular integrity assessment (MAIA) microperimeter. Fixation location was measured as distance in degrees (°) between preferred retinal locus (PRL) and estimated fovea location (EFL); fixation was defined as eccentric when the distance between PRL and EFL exceeded 2°. Fixation stability was graded as stable, relatively unstable, or unstable and expressed as bivariate contour ellipse area (BCEA, °²).

Main Outcome Measures

Fixation location and stability.

Results

The median distance of the PRL from the anatomic fovea was 0.7°, and fixation location was eccentric in 27% of eyes. Fixation was graded as stable in 64% of eyes, relatively unstable in 13%, and unstable in 24%, with a median 95% BCEA of 6.2°². The atrophic/fibrotic stage was associated with worse fixation parameters (all P < 0.01). Both PRL eccentricity and fixation stability were linearly associated with BCVA: every 1° increase in PRL eccentricity was associated with a 0.07 logarithm of the minimum angle of resolution (logMAR) worse BCVA (P < 0.0001) while every 1°² increase in 95% BCEA was associated with a 0.01 logMAR worse BCVA (P < 0.001). No significant intereye correlation was found for PRL eccentricity and fixation stability, as well as no association between the patient's age and fixation parameters.

Conclusions

We demonstrated that most eyes affected by BVMD retain a central stable fixation and provided evidence that both fixation eccentricity and stability are strongly associated with visual acuity in BVMD. These parameters may serve as secondary end points for future clinical trials.

Financial Disclosures

Proprietary or commercial disclosure may be found after the references.

Optical coherence tomography angiography in Bietti crystalline dystrophy

PURPOSE

Bietti crystalline dystrophy (BCD) is a rare autosomal recessive retinal dystrophy caused by pathogenic variants of CYP4V2 gene and characterized by shiny yellow deposits in the retina and progressive atrophy of the retinal pigment epithelium (RPE) and choriocapillaris. The main aim of the present study is to describe the optical coherence tomography angiography (OCTA) characteristics of a patient affected by BCD.

METHODS

A 59-years-old female with genetically confirmed BCD underwent an ophthalmological examination complete of OCTA performed in the atrophic retina, the junctional zone and the apparently normal retina. The area of choriocapillaris (CC) atrophy was compared to the area of RPE atrophy on fundus autofluorescence (FAF) imaging.

RESULTS

A severe vessel density (VD) deficit at the level of superficial and deep capillary plexa as well as CC was registered in atrophic areas, which resulted deeper with respect to the junctional area, whereas the apparently preserved retina revealed VD values similar to that of control eyes. The area of RPE atrophy on FAF was larger (55.90 mm2 in right eye and 48.76 mm2 in left eye) than the area of CC atrophy on OCTA imaging (51.86 mm2 and 42.44 mm2 respectively in right and left eye).

CONCLUSIONS

Our findings suggest that VD impairment of retinal plexa and CC follows the degeneration of RPE as demonstrated by the greater size of the area of RPE atrophy compared to CC atrophy. Further investigations based on OCTA imaging are necessary to enhance our knowledge of this rare disease.

variant associated with pigmented paravenous chorioretinal atrophy

PURPOSE

To report a case of Pigmented Paravenous Chorioretinal Atrophy (PPCRA) associated with a novel RPGRIP1 dominant variant.

METHODS

Case report. The patient underwent multimodal retinal imaging, including spectral-domain optical coherence tomography (OCT), OCT Angiography (OCTA), blue-light autofluorescence (BAF), and ultra-widefield pseudocolor retinography and autofluorescence. Genetic testing was performed using next-generation sequencing.

RESULTS

A 67-year-old male presented with a clinical suspicion of retinitis pigmentosa. His best-corrected visual acuity was 20/32 in the right eye and 20/200 in the left eye. On fundus examination, paravenous pigment clumping and chorioretinal atrophy were seen bilaterally, matching confluent hypoautofluorescent areas departing from the optic disc. This clinical presentation suggested a case of PPCRA. Genetic testing found a heterozygous deletion of nucleotide 631 (c.631del) in the RPGRIP1 gene, a frameshift variant that generates a premature stop codon (p.Ser211Valfs*64) and therefore results in a truncated or absent protein product. The variant was regarded as likely pathogenic (class IV).

CONCLUSION

In this report, we describe a case of PPCRA in association with a novel, likely pathogenic c.631del, p.Ser211Valfs*64 variant in RPGRIP1, a gene that has been associated with Leber congenital amaurosis and cone-rod dystrophy. Our case expands the spectrum of genes associated with PPCRA and prompts further studies to ascertain the molecular etiopathogenesis of this disease.

Peripheral Retinal Involvement in Extensive Macular Atrophy with Pseudodrusen-Like Deposits

PURPOSE

To describe the alterations of the peripheral retina in extensive macular atrophy with pseudodrusen-like deposits (EMAP) by means of ultrawidefield fundus photography (UWFFP) and ultrawidefield fundus autofluorescence (UWF-FAF).

STUDY DESIGN

Prospective, observational case series.

PARTICIPANTS

Twenty-three patients affected by EMAP.

METHODS

Each patient underwent best-corrected visual acuity (BCVA) measurement, UWFFP, and UWF-FAF. The area of macular atrophy, as well as the pseudodrusen-like deposits and peripheral degeneration, were assessed using UWF images, at baseline and over the follow-up.

MAIN OUTCOME MEASURES

The assessment of the clinical patterns of both pseudodrusen-like deposits and peripheral retinal degeneration. Secondary outcomes included assessing macular atrophy by means of UWFFP and UWF-FAF, and tracking progression over the follow-up.

RESULTS

Twenty-three patients (46 eyes) were included, of whom 14 (60%) were female. Mean age was 59.0 ± 5 years. Mean BCVA at baseline was 0.4 ± 0.4, declining at a mean rate of 0.13 ± 0.21 logarithm of the minimum angle of resolution/year. Macular atrophy at baseline was 18.8 ± 14.2 mm2 on UWF-FAF, enlarging at a rate of 0.46 ± 0.28 mm/year, after the square root transformation. Pseudodrusen-like deposits were present in all cases at baseline, and their detection decreased over the follow-up. Three main types of peripheral degeneration were identified: retinal pigment epithelium alterations, pavingstone-like changes, and pigmented chorioretinal atrophy. Peripheral degeneration progressed in 29 eyes (63.0%), at a median rate of 0.7 (interquartile range, 0.4-1.2) sectors/year.

CONCLUSIONS

Extensive macular atrophy with pseudodrusen-like deposits is a complex disease involving not only the macula, but also the midperiphery and the periphery of the retina.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Pigmented paravenous chorioretinal atrophy: Updated scenario

Pigmented paravenous chorioretinal atrophy (PPCRA) is an uncommon form of chorioretinal atrophy characterized by perivenous aggregations of pigment clumps associated with peripapillary and radial zones of retinal pigment epithelial atrophy that are distributed along the retinal veins. Most patients are asymptomatic, and evidence suggest that PPCRA is slowly progressing. Unless macular involvement is present, the majority of patients usually retain a normal visual function. Our ability to diagnose PPCRA has recently improved thanks to multimodal imaging, especially with the advent of ultra-widefield (UWF) imaging. Blood tests and functional and genetic testing can help with the correct differential diagnosis of pseudo-PPCRA or other disorders with similar characteristics. Although the cause of PPCRA is unknown, it is possible that it has a genetic basis. In this review we provide a summary of the multimodal imaging characteristics of PPCRA, and discuss its possible pathogenesis, based on the genes that have been associated with this disease.

Hyperautofluorescent Ring Pattern in Retinitis Pigmentosa: Clinical Implications and Modifications Over Time

Purpose

The purpose of this study was to investigate the relation among hyperautofluorescent ring patterns, visual acuity (VA), and optical coherence tomography (OCT) features in patients with retinitis pigmentosa (RP), and to describe its modifications over time.

Methods

This was a retrospective, longitudinal, and observational study. Clinical and imaging data from the first and last available visits of patients with a clinical diagnosis of RP were reviewed. The ellipsoid zone (EZ) width was measured on OCT acquisitions. Short-wavelength autofluorescence (SW-AF) images were classified based on the hyperautofluorescent ring pattern as absent, regular, and irregular, and their modifications over the follow-up were described. The VA, EZ width, and progression rate were compared among the three groups.

Results

One hundred eight eyes from 54 subjects were included in the study. The hyperautofluorescent ring was not present in 28 eyes (25.9%), appeared regular in 45 eyes (41.7%), and had an irregular pattern in 35 eyes (32.4%). The three groups differed in terms of age, VA, and EZ width (all P < 0.05). Additionally, the absence of a hyperautofluorescent ring indicated a faster rate of progression (P < 0.001). Throughout the follow-up period, 17 eyes (15.7%) experienced a change in the AF pattern, with irregular rings being more commonly affected.

Conclusions

The hyperautofluorescent ring is a useful tool to frame patients based on their EZ width and VA. We described its possible modifications over time, the knowledge of which can aid clinicians in the interpretation of imaging finding changes of their patients.

The Clinical Role of the Choroidal Assessment in High Myopia: Characteristics and Association With Neovascular and Atrophic Complications

Purpose

To investigate the clinical utility of choroidal quantitative assessment associated with the presence of macular neovascularization (MNV) or atrophy in high myopia.

Methods

The study was designed as a retrospective case series with two-year follow-up. We measured choroidal thickness (CT) and the presence and subtype of dome-shaped macula (DSM). In DSM eyes we also calculated the presence and type of choroidal deepening (CD). The eyes were categorized as Subgroup 1 (high myopia without complications), Subgroup 2 (high myopia complicated by MNV), and Subgroup 3 (high myopia complicated by macular or posterior pole atrophy). Main outcome measures were the detection of significant CT cutoffs associated with the three subgroups of eyes and the clinical impact of DSM and CD subtypes.

Results

Our cohort (190 eyes affected by high myopia) was categorized as Subgroup 1 (66 eyes), Subgroup 2 (72 eyes) and Subgroup 3 (52 eyes). Baseline CT values allowed to separate the subgroups with myopic-related complications (area under the curve = 0.85; P < 0.05). In Subgroup 1, vertical DSM was the most frequent (54%), with CD absence characterizing the 46% of cases. Round DSM was the most represented subtype in Subgroup 2 (49%), with 55% of sub-dome CD subtypes; in these cases, MNV resulted always localized in the fovea. Subgroup 3 equally shown horizontal or vertical DSM (53% and 47%, respectively), with 80% of cases showing peri-dome CD.

Conclusions

Choroidal quantitative assessment can categorize three high myopia subgroups. MNV subgroup is characterized by intermediate choroidal thinning and higher prevalence of round DSM with sub-dome CD.

Association Between Genotype and Phenotype Severity in ABCA4-Associated Retinopathy

Importance

ABCA4-associated retinopathy is a common inherited retinal disease, and its phenotype spans from late-onset macular dystrophy to extensive cone-rod degeneration. Over 2000 disease-causing variants in the ABCA4 gene have been identified.

Objective

To investigate genotype-phenotype correlations in ABCA4-associated retinopathy.

Design, Setting, and Participants

This cohort study took place at a single referral center for inherited retinal diseases in Italy. Data were prospectively acquired from January 2015 to June 2022. Patients diagnosed with an inherited retinal disease related to biallelic ABCA4 variants were included for analysis.

Exposure

Genotype, classified into 4 groups according to the presence of the (1) p.Gly1961Glu allele, (2) a hypomorphic allele, (3) at least 1 moderate variant (moderate genotypes), or (4) 2 biallelic severe variants (severe genotypes).

Main Outcomes and Measures

Total decreased autofluorescence (TDAF) and definitely decreased autofluorescence (DDAF) areas, inner and outer retinal volumes, and the respective progression rate.

Results

A total of 71 patients (median [IQR] age, 34 [22.4-47.2] years; 40 [56%] female) were included in the study, and 54 (76%) were followed up for a median (IQR) of 3.5 (1.6-4.7) years. Compared with moderate genotypes, those with the p.Gly1961Glu allele had smaller TDAF lesions by 61% (95% CI, -78% to -33%; P < .001) and DDAF lesions by 77% (95% CI, -93% to -18%; P = .02), along with slower growth rates for both TDAF (0.05 mm/y; 95% CI, 0.01-0.07; P < .001) and DDAF (0.06 mm/y; 95% CI, 0-0.12; P = .004). Hypomorphic alleles were associated with a thicker inner (+0.19 mm3; 95% CI, +0.02 to +0.36; P = .03) and outer retinal volume (+0.16 mm3; 95% CI, +0.03 to +0.28; P = .01) compared with moderate genotypes as well as a slower TDAF growth rate (0.05 mm/y; 95% CI, 0.01-0.08; P = .007). Severe genotypes had a 7-fold larger TDAF area (95% CI, 3.4-14.7; P < .001) and 11-fold larger DDAF area (95% CI, 2.9-42.1; P < .001) compared with moderate genotypes, along with faster growth rates estimated at 0.16 mm/y for TDAF (95% CI, 0.12-0.20; P < .001) and 0.17 mm/y for DDAF (95% CI, 0.12-0.23; P < .001).

Conclusions and Relevance

In this study of ABCA4-associated retinopathy, a 4-tier classification of genotypes was found to capture substantial variation in disease phenotype severity. These findings could prove beneficial for the prognostication of patients and warrant consideration of genotype in the design of future clinical trials.

Foveal Eversion is Associated with High Persistence of Macular Edema and Visual Acuity Deterioration in Retinal Vein Occlusion

INTRODUCTION

Foveal eversion (FE) is a recently described optical coherence tomography (OCT) finding associated with negative outcome in diabetic macular edema. The main goal of the present study was to investigate the role of the FE metric in the diagnostic workup of retinal vein occlusion (RVO).

METHODS

This study was a retrospective, observational case series. We included 168 eyes (168 patients) affected by central RVO (CRVO) and 116 eyes (116 patients) affected by branch (RVO). We collected clinical and imaging data from CRVO and BRVO eyes affected by macular edema with a minimum follow-up of 12 months. On structural OCT, we classified FE as pattern 1a, characterized by thick vertical intraretinal columns, pattern 1b, presenting thin vertical intraretinal lines, and pattern 2, showing no signs of vertical lines in the context of the cystoid macular edema. For statistical purposes, we considered data collected at baseline, after 1 year and at the last follow-up.

RESULTS

The mean follow-up was 40 ± 25 months for CRVO eyes and 36 ± 24 months for BRVO eyes. We found FE in 64 of 168 CRVO eyes (38%) and in 25 of 116 BRVO eyes (22%). Most of the eyes developed FE during the follow-up. For CRVO eyes, we found 6 eyes (9%) with pattern 1a, 17 eyes (26%) with pattern 1b and 41 eyes (65%) with pattern 2. Of those BRVO eyes with FE, we found 8 eyes (32%) with pattern 1a + 1b and 17 eyes (68%) with pattern 2. In both CRVO and BRVO the presence of FE was significantly associated with higher persistence of macular edema and worse outcome, with FE pattern 2 representing the most severe condition. Remarkably, FE patterns 1a and 1b were characterized by BCVA stability over the follow-up, whereas FE pattern 2 showed significant bestcorrected visual acuity (BCVA) worsening at the end of the follow-up.

CONCLUSIONS

FE can be considered a negative prognostic biomarker in RVO, associated with higher persistence of macular edema and worse visual outcome. Müller cell impairment might represent the pathogenic mechanism leading to the loss of macular structural support and impairment of fluid homeostasis.

HYPERREFLECTIVE BAND IN THE GANGLION CELL LAYER IN RETINITIS PIGMENTOSA

PURPOSE

To describe a sign that takes the form of a continuous hyperreflective band within the thickness of the ganglion cell layer (GCL), thus dubbed the "hyperreflective ganglion cell layer band" (HGB), which the authors detected in a fraction of patients affected by retinitis pigmentosa (RP).

METHODS

Retrospective, cross-sectional, observational study. Optical coherence tomography (OCT) images of patients with RP examined between May 2015 and June 2021 were retrospectively reviewed for the presence of HGB, epiretinal membrane (ERM), macular hole, and cystoid macular edema (CME). The ellipsoid zone (EZ) width was also measured. A subgroup of patients underwent microperimetry in the central 2°, 4°, and 10°.

RESULTS

One hundred and fifty-four eyes from 77 subjects were included in the study. The HGB was present in 39 (25.3%) eyes with RP. Mean best-corrected visual acuity (BCVA) was 0.39 ± 0.05 logMAR (approximately 20/50 Snellen equivalent) and 0.18 ± 0.03 logMAR (approximately 20/32 Snellen equivalent) in eyes with and without HGB, respectively ( P < 0.001). The two groups did not differ regarding EZ width; mean 2°, 4°, and 10° retinal sensitivity; and prevalence of CME, ERM, and macular hole. The multivariable analysis showed the presence of HGB to be a predictor of poorer BCVA ( P < 0.001).

CONCLUSION

HGB is an OCT finding detectable in approximately a quarter of eyes with RP and is associated with a poorer visual function. In the discussion, the authors speculate about possible morphogenetic scenarios to explain this observation.

HYPERREFLECTIVE FOCI PRECEDE MACULAR NEOVASCULARIZATION FORMATION IN ANGIOID STREAKS

PURPOSE

To describe the steps leading to the development and progression of macular neovascularization (MNV) in angioid streaks.

METHODS

The study was designed as retrospective, longitudinal case series. Patients with angioid streaks were investigated by means of multimodal imaging, including fundus autofluorescence and structural optical coherence tomography. Main outcome measures were hyperreflective foci and MNV progression steps.

RESULTS

Overall, 40 eyes (20 patients) affected by angioid streaks were evaluated. Over the follow-up, five eyes of five patients developed MNV. The mean follow-up was of 1.6 years. The mean number of anti-vascular endothelial growth factor injections was 4.35 ± 1.4. Mean best-corrected visual acuity was 0.53 ± 0.38 LogMAR at the MNV onset, improving to 0.42 ± 0.40 LogMAR at the end of the follow-up ( P > 0.05). Intraretinal hyperreflective foci onset and coalescence represented the first alterations occurring before the onset of the MNV. Anti-vascular endothelial growth factor treatment was associated with exudation relapsing and remitting, with still present intraretinal hyperreflective foci and pigment accumulation. The longitudinal analysis of our cohort of eyes outlined the event timeline: 1.2 months to find concentrated hyperreflective foci, 4.5 months to observe pigment organization through the outer nuclear layer, and 1.5 years to detect MNV.

CONCLUSION

Hyperreflective foci formation, concentration, and migration represent early alterations occurring before the onset of the MNV in angioid streaks.

FUNDUS AUTOFLUORESCENCE IN EXTENSIVE MACULAR ATROPHY WITH PSEUDODRUSEN AND DIFFUSE TRICKLING GEOGRAPHIC ATROPHY

PURPOSE

To establish whether extensive macular atrophy with pseudodrusen (EMAP) can be distinguished from the diffuse-trickling phenotype of geographic atrophy (DTGA) secondary to age-related macular degeneration on the basis of its features on blue-light autofluorescence.

METHODS

The authors reviewed our prospectively maintained database to enroll patients with a diagnosis of EMAP, DTGA, and non-DTGA with a minimum follow-up of 1 year. Atrophic areas and growth rates were measured on blue-light autofluorescence images, using the Heidelberg Region Finder tool. Circularity and roundness were chosen as atrophy shape descriptors, extracted using ImageJ, and compared between disease groups.

RESULTS

A total of 28 EMAP, 27 DTGA, and 30 non-DTGA eyes were included in the analysis. The median follow-up time was around 3.5 years. Extensive macular atrophy with pseudodrusen was characterized by an irregular and elongated shape (low circularity and low roundness) and associated with a fast atrophy growth rate (3.6 mm 2 /year), compared with non-DTGA. However, these parameters were not significantly different between EMAP and DTGA.

CONCLUSION

Our study found that EMAP and DTGA cannot be effectively differentiated on fundus autofluorescence. In both diseases, the macular atrophic area has a major vertical axis, fringed borders, and fast progression.

Confocal MultiColor Signal Depends on Perfusion Characteristics of Retinal Microaneurysms in Diabetic Retinopathy as Detected by OCTA

Purpose

To propose a noninvasive way of classifying multimodal imaging of retinal microaneurysms (MA) secondary to diabetic retinopathy (DR).

Methods

The research was designed as a cross-sectional, observational study of patients affected by DR. Multimodal imaging included confocal MultiColor imaging, optical coherence tomography (OCT) and OCT angiography (OCTA). MA green- and infrared-reflectance components were assessed by confocal MultiColor imaging, reflectivity properties by OCT, and MA perfusion features by OCTA. In addition, we included high-resolution (HR) and high-speed (HS) OCTA scans to assess HR-HS agreement in detecting retinal MA and to highlight different perfusion features detected by both OCTA acquisitions.

Results

We analyzed 216 retinal MAs, divided into green (46; 21%), red (58; 27%) and mixed types (112; 52%). Green MAs were mainly hyper-reflective on OCT, with no or poor filling on OCTA. Red MAs were characterized by an isoreflective signal on OCT and full filling on OCTA. Mixed MAs showed a hyper-reflective border and a hyporeflective core on OCT and partial filling on OCTA. No differences in red MA HR/HS size discrepancy and reflectivity were found, whereas these progressively increased as the MA MultiColor signal changed from infrared to green. MA types significantly correlated with visual acuity, DR duration, and DR severity.

Conclusions

Retinal MA can be classified reliably by means of a fully noninvasive multimodal imaging-based assessment. MA types are matched with visual acuity, DR duration and DR severity. Both HR and HS OCTA are highly effective in detecting MA, although HR OCTA is to be preferred in the presence of fibrotic evolution.

Translational Relevance

This study outlines a proposed novel MA classification based on noninvasive multimodal imaging. The findings presented in this paper endorse the clinical relevance of this approach, highlighting how this classification is associated with both DR duration and severity.

High-resolution/High-Speed Gap Can Distinguish Different Intraretinal Perfusion Signals by Optical Coherence Tomography Angiography

Purpose

The development of optical coherence tomography angiography (OCTA) has radically changed the diagnostic assessment of the intraretinal vascular network. Two different OCTA acquisition modalities have recently been introduced in clinical practice, namely high-resolution (HR) and high-speed (HS) scans. HR OCTA requires more acquisition time and provides higher quality data, whereas HS OCTA is faster but furnishes lower quality data. The main aim of the present study is to gauge how much extra blood flow perfusion information can be obtained through the combined use of HR and HS OCTA.

Methods

We compared HR and HS OCTA acquisitions to assess the reliability of both techniques, also putting forward a new set of quantitative metrics to measure the HR/HS OCTA gap and to highlight different perfusion information.

Results

In essence, both HR and HS OCTA acquisitions proved highly feasible in detecting the intraretinal vascular flow signal, as confirmed by the stability of quantitative OCTA metrics, thus displaying their suitability for use in clinical practice. We detected an HR/HS overlapping gap of 21.6 ± 6.5% for intraretinal capillaries, and 4.3 ± 1.2% for choriocapillaris, highlighting the greater information obtained by HR OCTA.

Conclusions

This novel HR/HS OCTA gap assessment might pave the way for the development of new quantitative metrics for retinal diseases that would focus on the earlier detection of perfusion impairment and relate it to the stage of the disease and its progression.

Translational Relevance

This study proposes a new quantitative way to detect different perfusion signals based on OCTA. The findings presented in this paper can lay the foundations for the development of new quantitative metrics focused on the separate analysis of high flow and low flow signals, enabling very early changes in intraretinal perfusion to be detected.

Quantitative multimodal imaging of extensive macular atrophy with pseudodrusen and geographic atrophy with diffuse trickling pattern

To compare clinical and imaging characteristics of extensive macular atrophy with pseudodrusen-like appearance (EMAP) versus diffuse-trickling geographic atrophy (DTGA) and non-diffuse-trickling geographic atrophy (nDTGA) phenotypes of age-related macular degeneration. Prospective, observational study performed in the Ophthalmology Department of IRCCS San Raffaele Hospital between January 2015 and January 2021. Patients examination included fundus autofluorescence (FAF) and optical coherence tomography at baseline and follow-up visits. We measured subfoveal choroidal thickness (SCT), Sattler/choroid ratio (SCR), choroidal vascularity index and ellipsoid zone disruption distance on OCT scans. We calculated progression rates and circularity of the atrophic lesions on FAF images. These variables were compared between the three groups and correlations with progression rates and visual acuity were assessed. Sixty-three eyes from 63 patients were included: 18 with EMAP, 18 with DTGA and 27 with nDTGA. Mean follow-up was 3.73 ± 2.12 years. EMAP and DTGA shared a faster progression, lower circularity and SCR, and higher EZ disruption distance than nDTGA, while SCT and CVI were similar between the three groups. Baseline circularity and SCR correlated with progression rates. EMAP and DTGA show similar OCT and FAF characteristics, which differ from nDTGA.

Understanding the propensity to undergo genetic testing in patients affected by inherited retinal diseases: a twelve-item questionnaire

BACKGROUND

The diagnosis of inherited retinal diseases (IRDs) can only be confirmed through genetic testing. The aim of our study is to investigate the propensity of Italian patients affected by IRDs to undergo genetic testing.

MATERIALS AND METHODS

One hundred and thirty-two patients diagnosed with IRDs referred to Italian Retina Onlus were enrolled from 1^st January 2021 to 31^th December 2021 in this cross-sectional study to answer to a twelve-item questionnaire.

RESULTS

One hundred and four patients were aware of the possibility of taking a genetic test, and 94 of them did. Most of genetically tested patients (93.6%) had been informed about advantages and limitations of genetic investigations. The most common reason for undergoing genetic testing was to gather information for their relatives, while the most frequent reason for patients not taking the test was lack of someone who encourages them to do so. Most of genetically tested patients believed that the results could aid medical research in the search for a treatment for IRDs, while who did not undergo DNA testing often did not have a clear opinion on the topic. Almost all patients (98.9%) performed the test through the Italian National Health System.

CONCLUSIONS

Our study investigated the tendency of Italian patients affected by IRDs to undergo genetic testing, highlighting the importance of educating both patients and healthcare professionals on this topic.

Optical Coherence Tomography Angiography in CRB1-Associated Retinal Dystrophies

AIM OF THE STUDY

To report optical coherence tomography angiography (OCTA) findings in patients affected by CRB1-associated retinal dystrophies.

METHOD

Patients affected by a genetically confirmed CRB1-associated retinal dystrophy were prospectively enrolled in an observational study, along with age- and sex-matched healthy volunteers as control subjects. All study and control subjects received a complete ophthalmic examination and multimodal retinal imaging, including OCTA.

RESULT

A total of 12 eyes from 6 patients were included in the study. The mean BCVA of patients was 0.42 ± 0.25 logMAR. Two patients showed large central atrophy, with corresponding definite hypo-autofluorescence on fundus autofluorescence (FAF). Another four patients disclosed different degrees of RPE mottling, with uneven FAF. On OCTA, the macular deep capillary plexus and choriocapillaris had a lower vessel density in eyes affected by CRB1-associated retinopathy when compared to healthy controls. On the other hand, vessel density at the peripapillary radial capillary plexus, superficial capillary plexus, and deep capillary plexus was significantly altered with respect to control eyes. Statistical analyses disclosed a negative correlation between the deep capillary plexus and both LogMAR best corrected visual acuity and central retinal thickness.

CONCLUSION

Our study reveals that CRB1-associated retinal dystrophies are characterized by vascular alterations both in the macular and peripapillary region, as assessed by OCTA.

Characterizing macular edema in retinitis pigmentosa through a combined structural and microvascular optical coherence tomography investigation

The aim of the study was to characterize macular edema (ME) in retinitis pigmentosa (RP) by means of quantitative optical coherence tomography (OCT)-based imaging. The study was designed as observational, prospective case series, with 1-year follow-up. All RP patients underwent complete ophthalmologic assessment, including structural OCT, OCT angiography, and microperimetry (MP). The primary outcome was the characterization through quantitative OCT-based imaging of RP eyes complicated by ME. A total of 68 RP patients' eyes (68 patients) and 68 eyes of 68 healthy controls were recruited. Mean BCVA was 0.14 ± 0.17 LogMAR at baseline and 0.18 ± 0.23 LogMAR at 1-year follow-up (p > 0.05). Thirty-four eyes (17 patients; 25%) showed ME, with a mean ME duration of 8 ± 2 months. Most of the eyes were characterized by recurrent ME. The ME was mainly localized in the inner nuclear layer in all eyes. LogMAR BCVA was similar in all RP eyes, whether with or without ME, although those with ME were associated with higher vessel density values, as well as thicker choroidal layers, than those without ME. In conclusion, the inner retina is closely involved in the pathogenesis of ME. The impairment of retinal-choroidal exchanges and Müller cell disruption might be a major pathogenic factor leading to the onset of ME in RP.

Peripheral and central capillary non-perfusion in diabetic retinopathy: An updated overview

Capillary non-perfusion (CNP) is one of the key hallmarks of diabetic retinopathy (DR), which may develop both in the periphery and at the posterior pole. Our perspectives on CNP have extended with the introduction of optical coherence tomography angiography (OCTA) and ultra-widefield imaging, and the clinical consequences of peripheral and macular CNP have been well characterized. Fluorescein angiography (FA) continues to be the gold standard for detecting and measuring CNP, particularly when ultra-widefield imaging is available. OCTA, on the other hand, is a quicker, non-invasive approach that allows for a three-dimensional examination of CNP and may soon be regarded as an useful alternative to FA. In this review, we provide an updated scenario regarding the characteristics, clinical impact, and management of central and peripheral CNP in DR.

PRPH2-Associated Retinopathy: Novel Variants and Genotype-Phenotype Correlations

PURPOSE

A broad spectrum of autosomal-dominant inherited retinal diseases (IRDs), ranging from mild macular pattern dystrophy to severe cone-rod degeneration, is associated with PRPH2 variants (peripherinopathies). We present detailed clinical and molecular characterization of patients affected by peripherinopathies, aiming to expand the mutational spectrum, and propose novel genotype-phenotype correlations.

DESIGN

Observational, retrospective case series.

PARTICIPANTS

Patients with an IRD related to a molecularly proven PRPH2 variant.

METHODS

Data from ophthalmic examinations and retinal imaging were collected for each follow-up visit. The standard imaging protocol included OCT, blue-light autofluorescence, near-infrared autofluorescence, and ultra-widefield fundus imaging. Genetic analysis was performed with a genomic approach by next-generation sequencing.

MAIN OUTCOME MEASURES

Results of ophthalmic examination, retinal imaging, and molecular genetic analysis.

RESULTS

Overall, a total of 19 patients with an IRD and a (likely) pathogenic PRPH2 variant were identified. Their age at presentation had a median of 48 years, whereas the symptomatic disease onset was in their 30s or 40s in 74% of cases. The median follow-up time was 4 years. Clinically, 6 patients were diagnosed with cone-rod dystrophy and 13 with pattern dystrophy. Among the 13 PRPH2 pathogenic variants identified in our cohort, 7 were missense, 3 nonsense, 2 frame shifting, and 1 splice site. Missense variants in the D2 loop were associated with cone-rod dystrophies and poor visual prognosis, whereas predicted loss-of-function alleles with pattern dystrophies and retention of a good visual function into adulthood. Overall, the following 7 variants were novel and never associated to a clinical phenotype: c.68delT, c.290G>A, c.413T>G, c.642C>G, c.702_706dupCAGTT, c.771_772delinsGA, and c.850C>G.

CONCLUSIONS

Here, we report the findings of a retrospective case series that provided a detailed clinical and molecular characterization of 19 patients harboring 13 different PRPH2 pathogenic variants, 7 of which were previously unreported, expanding the mutational spectrum of the PRPH2 gene. Loss-of-function variants might be preferentially associated with mild-pattern dystrophies, whereas missense dominant-negative variants might be preferentially associated with severely blinding cone-rod degenerations. Further studies are needed to better define the pathogenetic mechanisms and the functional effects of most variants to allow the development of successful gene therapy.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Clinical Correlation Between Optical Coherence Tomography Biomarkers and Retinal Sensitivity in Best Vitelliform Macular Dystrophy

Purpose

To investigate the clinical and imaging features associated with retinal sensitivity in Best vitelliform macular dystrophy (BVMD).

Methods

This was a cross-sectional, single-center, observational study. Each patient underwent optical coherence tomography (OCT), near-infrared fundus autofluorescence, and OCT angiography. Macular integrity assessment microperimetry under mesopic conditions was performed to obtain retinal sensitivity thresholds from 68 testing points in the central macula. Structural OCT was used to classify BVMD lesions into four types according to their composition: vitelliform, mixed, subretinal fluid, and atrophy. Multilevel, mixed-effects linear regression was used to determine the factors associated with retinal sensitivity.

Results

The study included 57 eyes of 30 patients with BVMD, 48 of which (84%) were in a clinical stage. Mean retinal sensitivity varied according to the composition of the lesion: the vitelliform type registering the highest (22 ± 4.1 dB), followed by mixed (18.73 ± 2.7 dB), subretinal fluid (15.68 ± 4.2 dB), and atrophy types (11.85 ± 4.6 dB). The factors most strongly associated with mean retinal sensitivity in BVMD proved to be the OCT lesion type and outer nuclear layer thickness.

Conclusions

Retinal sensitivity in BVMD is influenced by lesion composition and outer nuclear layer thickness. Further studies with long-term follow-up are warranted to examine retinal sensitivity over time and to validate retinal sensitivity changes as biomarkers for BVMD.

Translational Relevance

Assessing retinal sensitivity in BVMD provides a new instrument in the clinical characterization of the disease and offers the opportunity to identify imaging biomarkers for use as outcome measures in future clinical trials.

Neuroinflammation and neurodegeneration in diabetic retinopathy

Diabetic retinopathy (DR) is the most common complication of diabetes and has been historically regarded as a microangiopathic disease. Now, the paradigm is shifting toward a more comprehensive view of diabetic retinal disease (DRD) as a tissue-specific neurovascular complication, in which persistently high glycemia causes not only microvascular damage and ischemia but also intraretinal inflammation and neuronal degeneration. Despite the increasing knowledge on the pathogenic pathways involved in DR, currently approved treatments are focused only on its late-stage vasculopathic complications, and a single molecular target, vascular endothelial growth factor (VEGF), has been extensively studied, leading to drug development and approval. In this review, we discuss the state of the art of research on neuroinflammation and neurodegeneration in diabetes, with a focus on pathophysiological studies on human subjects, in vivo imaging biomarkers, and clinical trials on novel therapeutic options.

Multimodal imaging evaluation of occult macular dystrophy associated with a novel RP1L1 variant

Purpose

Occult Macular Dystrophy (OMD) is an autosomal dominant inherited retinal dystrophy caused by mutations in the retinitis pigmentosa 1-like 1 (RP1L1) gene. The present study describes a novel RP1L1 variant, identified for the first time in two Italian sisters diagnosed with OMD, along with multimodal imaging features, including Optical Coherence Tomography (OCT) Angiography.

Methods

We performed multimodal imaging including spectral-domain OCT, blue light autofluorescence (BAF), infrared autofluorescence (IRAF), swept-source OCT Angiography (OCTA), full-field and multifocal electroretinography. Genetic analysis was performed using Next-Generation Sequencing. Pathogenic potential of nonsynonymous novel variants was scored with two in silico algorithms.

Results

Proband 1 (P1) and proband 2 (P2) were two Italian sisters of 61 and 56 years old. Both reported a history of progressive visual loss without fundoscopic alterations. P1 reported a 4-year history of rapid visual function worsening, and her best-corrected visual acuity (BCVA) was counting fingers in both eyes. P2 reported a 20-year history of mild but progressive visual acuity loss, and her BCVA was 1/10 and 2/10 respectively in her right and left eye. Structural OCT displayed disorganization of outer retinal bands at the macula and foveal cavitation; loss of foveal photoreceptors was remarkably evident on en-face OCT slabs. OCTA quantitative analysis found that vessel density was reduced both at SCP and DCP while choriocapillaris blood flow was relatively spared. Genetic analysis found the same rare dominant c.2873G > C, p.Arg958Pro variant in the RP1L1 gene. The substitution was regarded as moderately radical according to Grantham score while PolyPhen2 classified the amino acidic substitution as probably damaging.

Conclusions and importance

Our study expands the mutational spectrum of RP1L1 gene: the rare c.2873G > C, p.Arg958Pro missense variant may be considered a new pathogenic variant for OMD, the first to be identified exclusively in an Italian family. Moreover, our quantitative OCTA data suggest that OMD is characterized by a rarefaction of superficial and deep capillary plexus.